Astrophotography is an interesting challenge, but a challenge anyone with a telescope can take on. The pursuit has been made infinitely more rewarding since the move from film to digital. By letting a camera's sensor "collect" photons over time, the telescope can reveal images not visible to the naked eye, no matter how dark the sky. And unlike the days of shooting with film, digital imaging results can be seen almost immediately.
However, taking images of dim points of light at night still has plenty of difficulties, one of which is getting the focus spot-on. Getting it right was a LOT of trial and error. Things were made less frustrating when Pavel Bahtinov gave the world the Bahtinov Mask. The mask made use of an interesting phenomenon known as diffraction. It is very clever and the use of a diffraction mask made focusing by eye easier, but still subjective. That is because even though such a visual-only technique can be pretty good for observing (subject to the expertise of the user), it is usually insufficiently precise or repeatable for astrophotography.
In order to to address those deficiencies, Dr. Winter of Gold Astro designed the GoldFocus system. For those interested in the details, there is an extensive discussion on focus and collimation on the Gold Astro site. The Gold Astro method, by using a combination of a proprietary mask and software, is an objective approach to achieving critical focus, unlike the subjectivity of the experience of the user. While the principle of the GoldFocus mask is the... [more] - Gold Astro FirstLook
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